Self-host Condensation

Condensation is a general-purpose distributed data system aimed at developers who want applications where users keep ownership of their data. It organises data locally into flexible documents, turns each document into an immutable chain of hashed objects, and merges copies with a join-semilattice merge function, so synchronization never produces conflicts and only recent changes cross the network. Encryption and signing happen inside the application, which means whatever backend you point it at - a directory store, a PHP HTTP store on files or MySQL/MariaDB, a small FTP server or a public cloud - only ever sees ciphertext. You can run your own store by installing the downloadable PHP store scripts (store.php plus an admin.php) behind a web server, by starting an HTTP store server with the cds command-line tools, or by using the folder store, which needs no store server at all. Client libraries are listed for Perl (command line), JavaScript (web) and Java for Android, the last of which is not published yet; the README says the Java implementation is stable but still being packaged, the website calls itself work in progress, and the repository was last pushed in 2022, so treat it as an experimental foundation rather than a turnkey service.